Reversing valve-gear.



No. 777,587'. PATENTED DEG. 13, 1904. E. BELKNAP.

RBVERSING VALVE GEAR.

APPLITION FILED .AUGA 6. 1904.

N0 MODEL.

l mentor UNTTED STATES;

Patented December 13, 1904,l

PATENT OEEICE.

PEVERSING VALVE-GEAR..

SPECIFICATION forming part of Letters Patent N0. 777,537, dated December 13, 1904-..

Application led August 6, 1904. Serial No. 219,753. (No model.)

Be it known that I, ELLswon'ru BuLuNAr, a citizen of the United States, residing at Cape Girardeau, in the county oi" Cape Girardeau and State ot' Missouri, have invented new and useful Improvements in Reversing' Valve- Gear, oi which the following is a spccilication.

My invention pertains to valvegear for steam-engines; and it has tor its object to provide a reversing valve-gear calculated to el'lect a perfect cut-oil at any point of the stroke and one which is simple, compact, and durable and is therefore well adapted to withstand the usage to which such devices are ordinarily subjected.

rlhe invention will be fully understood from the following description and claims when taken in connection with the accompanying drawings, forming part of this specilication, in which- Figure l is a diagrammatic View of so much ot' a compound engine as is necessary to illustrate the application of my improvements. Fig. 2 is an enlarged view, partly `in section and partly in elevation, of my novel revers ing-gear. Fig. 3 is a detail diametrical seetion illustrating the relative arrangement of the slots in thc inner and outer cccentrics comprised in the gear. Fig. 4 is a side elevation of the outer eccentric on an enlarged scale. Fig. 5 is a similarl view ot' the inner eccentric, and Fig. 6 is an enlarged side elevation illustrating a portion of the reversing'-rod and the pin and antii'riction-rollers carried thereby.

Similar letters designate corresponding parts in all of the views ot' the drawings, re* ferring to whichl A is the high-pressure cylinder, and B the lowpressure cylinder, of a compound engine, which cylinders are set at angles oi" forty-'live degrees, as illustrated in Fig. l. The said cylinders are provided with the usual valvcchests Ct, in which may be arranged valves of any type compatible with the purposes of my invention.

C C are cross-heads connected with the pistons in the cylinders A and B.

D D are main bearings, and E is the main shaft of the engine, which shat't is journaled in the said bearings D and carries at one end a crank-disk lil between a single crank-pin (di, on which and the cross-heads U are interposed connection-rods H.

The shaft lil, which is tubular and is provided with a longitudinal slot Fig. 2, forms part of my novel valve-gear, and in addition to the said shaft E the gear comprises an endwise-movable or thrust rod l, having a circumferential groove c adjacent to its outer end, a pin d, carried by said rod l and extend ing through and adapted to move in the slot of the main shaft, antifrictionrollers and j'. mounted on the pin (Z and designed for a purpose presently set iforth, a hand-lever Ji, connected, through the medium oi" a link K, to one ot' the main lfiearings D, a collar g, arranged in the groove c oi the rod l and having trunnions /t journalcd in the hand-lever, an inner eccentric L, interposed between and abutting at its ends against the bearings l) and loosely su `rrounding the main shaft E, and an outer eccentric M, loosely surrounding the eccentric L and carrying a cam N, which is connected tothe valves in the chests a through the medium ot' the usual strap and rods j, as shown in Fig. 1. The eccentrics L and M are provided, as best shown in Figs. 3, 4. and 5, with oblif]ucly-disposcd slotsl and ym. These slots and m intersect each other, as shown by dotted lines in Fig. 3, and are designed to receive the antilriction-rollers e and f, respectively.

In virtue oi' the construction and relative arrangen'ient of the parts comprised in my novel gear, as above described, it will be observed that the eccentric L is adapted to revolve in the eccentric M and that thc throw of the two cccentrics is the same and that the throws together are equivalent to the full travel of the valves. 1t will also be observed that when the rollers e and f are moved toward the center by manipulation of the hand-lever J the large portions of the eccentrics L and M will be caused to assume positions opposite each other, and in consequence the earn N will run true with center oit' shaft and the valves will be positioned so as to stand neutral and cover both ports. This affords a perfect cutoff and is materially advantageous for such reason. lt will further be noted that the con- IOO struction of my novel gear is such that the engine can be reversed under full load without the manipulation of an intercepting valve or other device, and consequently the gear conduces to economy of fuel.

By reason of the outer eccentric M being connected, through the medium of the strap z' and rods j', with the valves of the high and low pressure cylinders and the cylinders being set at angles of forty-five degrees there is no liability of the engine getting on the center,

and hence no difficulty in starting the engine.

It will be appreciated from the foregoing that in addition to the advantages which I have ascribed to my novel valve-gear the same is very compact and is made up of but few parts no one of which is liable to wear out or be broken after a short period of use.

I have entered into a detailed description of the construction and relative arrangement of the parts embraced in the present and preferred embodiment of my invention in order to impart a full, clear, and exact understanding of the same. I do not desire, however, to be understood as confining myself to such specific construction and relative arrangement of parts, as such changes or modifications may be made in practice as fairly fall within the scope of my invention as claimed.

It is obvious that in lieu of inter-posing the inner and outer eccentrics between bearings D said eccentrics might in a large engine be interposed between a bearing and a collar fixed on the main shaft.

Having described my invention, what I claim, and desire to secure by Letters Patent,

l. In a reversing valve-gear, the combination of high and low pressure cylinders set at angles, valves complementary to the cylinders, a shaft, driving connections between the pistons in the cylinder and the shaft, in-

ner and outer eccentrics mounted on the shaft, means for simultaneously turning the eccentrics in opposite directions, and connections between the outer eccentric and the valves for actuating the latter by the former.

2. In a reversing valve-gear, the combination of a cylinder, a valve complementary thereto, a shaft, a driving connection between a piston in the cylinder and the shaft, inner and outer eccentrics mounted on the shaft, means for simultaneously turning the eccentrics in opposite directions, and a connection between the outer eccentric and the valve for actuating the latter by the former.

3. In a reversing valve-gear, the combination of a main shaft adapted to be connected with a piston in an engine-cylinder, an endwise-movable rod disposed in said shaft, and having a pin arranged to work in a slot thereof, inner and outer eccentrics surrounding the shaft and having slots arranged to intersect each other and receive the pin of the endwisemovable rod, and a cam on the outer eccentric adapted to be connected with the valve complementary to the said engine-cylinder.

4. A reversing valve-gear comprising a tubular shaft adapted to be connected with a piston in an engine-cylinderl and having a longitudinal slot, an endwise-movable rod disposed in the tubular shaft, and having a pin extending through and adapted to move in the slot thereof, inner and outer eccentrics surrounding the shaft and having diagonal slots intersecting each other and receiving the pin of the endwise-movable rod, a cam on the outer eccentric adapted to be connected with the valve complementary to the said engine cylinder, and a hand-lever connected with and adapted to move the endwise-movable rod.

5. A reversing valve-gear comprising a shaft adapted to be connected with a piston in an engine-cylinder, inner and outer eccentrics mounted on the shaft, means on the outer eccentric for transmitting motion to a valve complementary to the said engine-cylinder, an endwise-movable device, and coacting means in the eccentrics and on the endwise-movable device for simultaneously turning the eccentrics in opposite directions incident to endwise movement of the said device.

6. A reversing valve-gear comprising a shaft adapted to be connected with a piston in an engine-cylinder, inner and outer eccentrics mounted on the said shaft, and having diagonal slots intersecting each other, means on the outer eccentric for transmitting motion to a valve complementary to the said enginecylinder, an endwisemovable rod, and means carried by said rod and arranged in the slots of the eccentrics whereby when the rod is moved endwise, the eccentrics will be simultaneously turned in opposite directions.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

ELLSWORTH BELKNAP.

Yitnesses:

WILLIAM H. DIoNIrP, GEORGE S. PATTERSON.

IOO 

